多箱式组合梁桥梁格模型截面特性修正研究

为了建立合理的梁格模型截面刚度取值方法,以一分离式钢混组合箱梁桥为对象建立三维板壳元模型,利用其计算结果修正梁单元截面刚度。结果表明:在偏载作用下,梁格模型计算精度较低;遗传算法修正截面参数后能有效地提高梁格模型计算精度;划分梁格时,纵向梁格划分宜偏向边梁,纵梁抗扭刚度宜按换算截面计算值的70%~80%取值。

On Sectional Properties Correction of Grillage Model of Composite Bridges with Multi-box Girder

In order to obtain rational section stiffness of grillage model,a three-dimensional shell finite element model for a separative steelconcrete composite box-girder bridge is built,with the result of the model,the section stiffness of beam elements is modified.The results indicate that the precision of grillage mode is low in the partial load;the precision of grillage mode will be improved with the sectional parameters corrected by genetic algorithm;in the grillage model,the division of longitudinal girder should lean to the fringe girder,the torsional stiffness of longitudinal grid should be valued according to 70% ~ 80% of the transformed section calculation results.